SYMPTOM
When opening the “Devices” folder within “Administration” in Strategy Developer the error below is received and the devices are not displayed.

Object variable or with block variable not set

2.Set the search to only include the object type “Device” and select “Find Now.

3. Within the list of returned devices, right click a device and select “Search for Components…”
4. If the component search returns a Transmitter object, proceed to the next Device and search for its components.
5. Repeat steps 3-4 until a device is found which has no components.
6. Once identified, launch Object Manager, connect to the environment, and select Tools -> "Create Configuration Package".
7. Within here add in the problematic device by performing the same search from Step 2 and dragging it into the package.
8. Change the "Action" to be "Delete" and select Proceed. (This will create a Delete package which can be imported into the environment to remove the object)

9. Once created, go to Tools -> "Import Configuration Package". and import the newly created package.
This will delete the problematic Device object.